JPWO2017110087A1 - Sound playback device - Google Patents

Abstract

Provided is a sound reproducing device capable of accurately adjusting an alarm sound output from a speaker. The sound reproduction device (1) is configured to output a sound from a speaker unit (10) having a speaker (12) and an identifier (14) for identifying the characteristics of the speaker (12), and sound output from the speaker (12). And an amplifier unit (20) for amplifying a corresponding signal. The amplifier unit (20) amplifies the signal input from the sound source (21) and outputs the amplified signal to the speaker (12), the determination unit (24), and the amplification degree adjustment unit (26). Have When the speaker unit (10) and the amplifier unit (20) are connected, the determination unit (24) determines the characteristics of the speaker (12) from the identifier (14) of the connected speaker unit (10). The amplification degree adjustment unit (26) adjusts the amplification degree of the signal output from the amplifier (22) in accordance with the characteristics of the speaker (12) determined by the determination unit (24).

Description

  The present disclosure relates to a sound reproducing device.

  Since electric vehicles and hybrid vehicles have low noise, there is a problem that it is difficult for pedestrians or the like to notice the approach of the vehicle when traveling at low speed with low self-vehicle road noise. For this reason, low noise vehicles such as electric vehicles and hybrid vehicles are provided with a sound reproducing device that generates an alarm sound that is a continuous sound reminiscent of the traveling state of the vehicle during traveling. By this alarm sound, a pedestrian or the like recognizes that the vehicle is approaching.

  A conventional sound reproduction device includes, for example, a speaker and a mechanism for adjusting the sound volume (sound pressure) from the speaker, and reduces the variation in sound pressure by calibrating the sound pressure output from the speaker. Alarm sound is output (see, for example, Patent Documents 1 and 2).

JP 2003-32777 A JP 2013-46140 A

  However, the variation in the sound pressure of the alarm sound output by the speaker is larger than the variation in the electric circuit system such as the amplifier unit that drives the speaker, and the speaker is adjusted by itself before attaching the speaker to the vehicle. After attaching to the vehicle, it is difficult to output an alarm sound having a desired sound pressure.

  This is due to the following background, in addition to the fate that the variation of speakers as electroacoustic transducers is larger than the variation of electric circuit systems due to its structure.

  That is, in order to make a pedestrian outside the vehicle surely recognize that the vehicle is approaching by an alarm sound, it is necessary to output a minimum necessary volume corresponding to this. For this reason, if the amplifier unit is adjusted so that a minimum required volume can be secured in accordance with a speaker having a low sound pressure level in consideration of a speaker having a large variation, it is possible to output a required volume. However, when a speaker with a high sound pressure level is applied to the adjustment state of the amplifier unit, the output sound volume becomes too high, giving the passengers in the vehicle uncomfortable feeling that the sound volume of the alarm sound is too high. . In this case, there is a problem that the merits of the electric vehicle and the hybrid vehicle, which originally have one of the features of being silent, are impaired.

  In addition, it is possible to adjust the sound pressure by collecting and analyzing the alarm sound output from the speaker after the speaker is attached to the vehicle. In this case, it is difficult to adjust the alarm sound output from the speaker with stable accuracy because the influence of disturbance is large.

  Therefore, an object of the present disclosure is to provide an acoustic reproduction device that can adjust an alarm sound output from a speaker with high accuracy and at low cost.

  An acoustic reproduction device according to an aspect of the present disclosure includes a speaker, a speaker unit having an identifier for identifying the characteristics of the speaker, and an amplifier that amplifies a signal corresponding to sound output from the speaker. . The amplifier unit amplifies a signal input from a sound source and outputs the amplified signal to a speaker, a determination unit that determines the characteristics of the speaker based on an identifier, and an amplification degree adjustment unit that adjusts the amplification degree of the signal output from the amplifier Have When the speaker unit and the amplifier unit are connected, the determination unit determines the characteristics of the speaker of the connected speaker unit from the identifier of the connected speaker unit. The amplification degree adjustment unit adjusts the amplification degree of the signal output from the amplifier in accordance with the characteristics of the speaker determined by the determination unit.

  These general or specific aspects may be realized by a system, a method, an integrated circuit, a computer program, or a recording medium such as a computer-readable CD-ROM. The system, method, integrated circuit, computer program Also, any combination of recording media may be realized.

  The invention according to the present disclosure can provide a sound reproducing device capable of accurately adjusting an alarm sound output from a speaker.

  Therefore, pedestrians outside the vehicle can fully recognize that the vehicle is approaching with an alarm sound of an appropriate volume, and the passengers in the vehicle are not likely to be alarmed by the volume of the alarm sound being too high. Pleasure can be prevented.

It is the schematic which shows the structure of the sound reproduction apparatus concerning embodiment. It is the schematic which shows the structure of the speaker unit concerning embodiment. It is a figure which shows the example of a speaker characteristic and an identifier. It is a figure which shows the procedure of sound reproduction operation | movement. It is a figure which shows the other structure of a speaker unit. It is a figure which shows other structure of a speaker unit. It is a figure which shows other structure of a speaker unit.

(Knowledge that became the basis of the present invention)
A conventional sound reproducing device includes, for example, a speaker and a mechanism that adjusts the volume (sound pressure) from the speaker, and adjusts (calibrates) the sound pressure output from the speaker, thereby adjusting the sound pressure. Outputs alarm sound with reduced variation.

  For example, Patent Literature 1 describes a volume control device connected to a speaker via a signal line. This volume adjusting device outputs a calibration signal to a signal line, and detects an output signal of the speaker generated when the calibration signal is given to the speaker. Then, the impedance of the speaker is detected based on the output signal, and the volume output from the speaker is adjusted based on the detected impedance.

  Patent Document 2 discloses an electronic device having a recording / playback function for audio signals. In this electronic device, the sensitivity of the left and right microphones can be corrected by the calibration process, and the audio signal can be recorded with a natural stereo feeling.

  However, generally, the variation in sound pressure for each speaker is large, and in the techniques described in Patent Documents 1 and 2, adjustment is performed by the speaker alone before the speaker is attached to the vehicle, and a desired value after the speaker is attached to the vehicle. It is difficult to guarantee sound pressure. It is also possible to calibrate the sound output from the speaker after the speaker is attached to the vehicle, analyze it, and calibrate the sound pressure. In this case, it is difficult to perform calibration with stable accuracy because the influence of disturbance is great.

  Regarding a warning sound output from a low noise vehicle such as an electric vehicle and a hybrid vehicle, the definition of the minimum sound pressure value is being studied in the North American National Highway Traffic Safety Administration (NHTSA). For example, the sound pressure of the speaker is set so that a minimum sound pressure value is defined for an 8 frequency band of 1/3 octave, and an alarm sound exceeding the minimum sound pressure value is output when measured by a predetermined measurement method. It needs to be adjusted.

  Therefore, an audio reproduction device according to one aspect of the present disclosure amplifies a signal corresponding to sound to be output from a speaker, a speaker unit having a speaker, an identifier for identifying characteristics of the speaker, and the like. And an amplifier section. Among them, the amplifier unit amplifies the signal input from the sound source and outputs it to the speaker, the determination unit that determines the characteristics of the speaker by the identifier, and the gain adjustment that adjusts the gain of the signal output from the amplifier Part. And when a speaker unit and an amplifier part are connected, a determination part determines the characteristic of the speaker of the connected speaker unit from the identifier of the connected speaker unit. The amplification degree adjustment unit adjusts the amplification degree of the signal output from the amplifier in accordance with the characteristics of the speaker determined by the determination unit.

  According to this, by providing the speaker unit with an identifier having identification information unique to the speaker, it is possible to determine the variation in the speaker characteristics such as the sound pressure unique to each speaker by the amplifier unit so that the optimum speaker characteristics are obtained. Can be adjusted. Therefore, when the speaker unit and the amplifier unit are connected, the alarm sound output from the speaker can be accurately adjusted by determining the identifier of the speaker. Therefore, a desired sound pressure characteristic can be realized no matter what speaker unit and amplifier unit are combined.

  The identifier may be a resistor having a resistance value corresponding to the characteristics of the speaker.

  According to this, the speaker characteristics of the speakers in the plurality of speaker units can be easily determined using a predetermined resistance value.

  The identifier may be a sound collection element that detects sound output from the speaker.

  According to this, since the identifier and the level are determined directly from the alarm sound output from the speaker, the alarm sound can be adjusted in real time.

  The identifier may be a vibration detection element that detects vibration of the speaker.

  According to this, since the identifier and the level are directly determined by detecting the vibration of the speaker corresponding to the alarm sound, the alarm sound can be adjusted in real time.

  The vibration detection element may be configured by a piezoelectric element.

  According to this, by using a piezoelectric element as a vibration detecting element, mechanical vibration called vibration of a speaker can be efficiently converted into an electric signal and adjustment can be easily performed.

  The vibration detection element may be configured by a light detection element.

  According to this, since the identifier and the level are directly determined from the vibration of the speaker corresponding to the alarm sound, the alarm sound can be adjusted in real time. In addition, since the vibration of the speaker is detected in a non-contact manner using light, it is possible to perform an accurate adjustment.

  Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. Note that each of the embodiments described below shows a specific example of the present invention. The numerical values, shapes, materials, constituent elements, arrangement positions and connecting forms of the constituent elements, steps, order of steps, and the like shown in the following embodiments are merely examples, and are not intended to limit the present invention. In addition, among the constituent elements in the following embodiments, constituent elements that are not described in the independent claims indicating the highest concept are described as optional constituent elements.

(Embodiment)
First, the configuration of the sound reproducing device according to the present embodiment will be described. FIG. 1 is a schematic diagram illustrating a configuration of a sound reproducing device according to an embodiment. FIG. 2 is a schematic diagram illustrating the configuration of the speaker unit according to the embodiment. FIG. 3 is a diagram illustrating examples of speaker characteristics and identifiers.

  As shown in FIG. 1, the sound reproducing device 1 includes a speaker unit 10 and an amplifier unit 20.

  The speaker unit 10 includes a speaker 12 and an identifier 14 indicating the characteristics of the speaker. The speaker unit 10 may include a speaker box to which the speaker 12 is attached.

  The speaker 12 outputs an alarm sound for notifying the approach of the vehicle to the outside. Since the alarm sound is generated toward a pedestrian or the like outside the vehicle, the speaker 12 is installed outside the vehicle. The speaker 12 has a function of converting an electrical signal into mechanical vibration, and outputs a sound pressure (sound volume) alarm sound based on the electrical signal. Note that the speaker 12 not only functions as a sound output element (speaker) that converts an electrical signal into mechanical vibration, but also functions as a sound collection element (microphone) that converts mechanical vibration into an electrical signal.

  The identifier 14 is an element having identification information for identifying the characteristics of the speaker 12. For example, as shown in FIG. 2, the identifier 14 includes a resistor 14a. The resistor 14 a has a resistance value corresponding to the characteristics of the speaker 12. By configuring the identifier 14 with the resistor 14a, it is possible to easily determine the characteristics of the speakers of the plurality of speaker units using a predetermined resistance value.

  Hereinafter, a case where the characteristics of the speaker 12 are set to sound pressure characteristics (sound pressure level) will be described.

  The resistance value of the resistor 14a is determined in advance according to the sound pressure obtained by measuring the sound pressure of the speaker 12 in advance. For example, as shown in FIG. 3, when the sound pressure level is low (level A), the resistance value R1, when the sound pressure level is medium (level B), the resistance value R2, and the sound pressure level is high (level C). In this case, the resistance value R3 is determined according to the sound pressure level. The sound pressure level is a level when the sound pressure is divided for each value in a predetermined range. The range of each sound pressure level may be arbitrarily determined.

  As shown in FIG. 1, the amplifier unit 20 includes a sound source 21, an amplifier 22, a determination unit 24, and an amplification degree adjustment unit 26.

  The sound source 21 is a sound source that generates an electrical signal corresponding to an alarm sound that informs the vehicle of approaching to the outside. The alarm sound is, for example, an engine sound. In this case, the sound source 21 often uses pseudo engine sound or electronic sound, and is composed of, for example, a bass part of 300 Hz to 500 Hz and a frequency component of 1 kHz to 3 kHz. Also, a simple sine wave signal sound or the like may be used. The sound source 21 may not be provided in the amplifier unit 20, but may be provided outside the amplifier unit 20 and connected to the amplifier 22 externally.

  The amplifier 22 amplifies a signal (electric signal) corresponding to the sound output from the sound source 21 with a predetermined amplification degree and outputs the amplified signal to the speaker 12. The amplification degree at this time is determined by the amplification degree adjustment unit 26 described in detail later. The amplifier 22 may be an analog amplifier or a digital amplifier.

  The determination unit 24 determines the identifier 14 of the speaker 12 and outputs the determination result to the amplification degree adjustment unit 26. The determination unit 24 is constituted by, for example, a microcomputer (microcomputer). The determination unit 24 stores in advance the speaker characteristics (sound pressure level in this case) of the speaker 12, the resistance value of the resistor 14a, and the sound pressure correction value in association with each other. For example, as shown in FIG. 3, when the speaker characteristic of the speaker 12 is A, R1 is stored as the resistance value of the resistor 14a, and +3 dB is stored as the sound pressure correction value.

  The determination unit 24 measures the resistance value of the resistor 14 a that constitutes the identifier 14. For example, the determination unit 24 measures the resistance value of the resistor 14 a by measuring the voltage value and the current value at both ends of the identifier 14. The determination unit 24 determines the characteristics of the speaker 12 based on the measured resistance value. The determination unit 24 determines a sound pressure correction value corresponding to the determined characteristics of the speaker 12. The determination unit 24 outputs the determined sound pressure correction value to the amplification degree adjustment unit 26. The determination unit 24 may directly measure the resistance value of the resistor 14a.

  The amplification degree adjustment unit 26 adjusts the amplification degree of the electric signal amplified by the amplifier 22. Specifically, the amplification degree adjustment unit 26 adjusts the amplifier 22 so that the electric signal corresponding to the alarm sound is amplified by the sound pressure correction value output from the determination unit 24 in the amplifier unit 20. The amplification degree adjustment unit 26 is configured by, for example, a DSP (Digital Signal Processor).

  In addition, the determination part 24 and the amplification degree adjustment part 26 may be comprised with the same apparatus by the microcomputer etc.

  Next, the sound reproduction operation in the sound reproduction device according to the present embodiment will be described. FIG. 4 is a diagram showing the procedure of the sound reproduction operation.

  When the speaker unit 10 and the amplifier unit 20 are connected, the determination unit 24 determines the characteristics of the speaker 12 of the connected speaker unit 10 from the identifier 14 of the connected speaker unit 10, and the amplification degree adjustment unit 26. Adjusts the amplification degree of the sound pressure output from the amplifier 22 in accordance with the characteristics of the speaker 12 determined by the determination unit 24.

  As shown in FIG. 4, first, the amplifier unit 20 is connected to the speaker unit 10 (step S11).

  Next, the determination unit 24 determines the identifier 14 of the speaker 12 (step S12). As described above, the determination unit 24 measures the resistance value of the resistor 14 a constituting the identifier 14 by measuring the voltage value and the current value at both ends of the identifier 14. Then, the determination unit 24 determines the characteristics of the speaker 12 based on the measured resistance value. Further, the determination unit 24 outputs a sound pressure correction value corresponding to the determined characteristic of the speaker 12 to the amplification degree adjustment unit 26.

  Next, the amplification degree of the amplifier 22 is adjusted based on the determination result of the identifier 14 by the determination unit 24 (step S13). The amplification degree of the amplifier 22 is adjusted by the amplification degree adjustment unit 26.

  The amplification degree adjustment unit 26 adjusts the amplification degree of the amplifier 22 based on the determination result of the determination unit 24. Specifically, the amplification degree adjustment unit 26 adjusts the amplifier 22 so that the electric signal corresponding to the alarm sound is amplified by the sound pressure correction value output from the determination unit 24 in the amplifier unit 20.

  Subsequently, the amplifier 22 outputs the adjusted electrical signal to the speaker 12. Thereby, the speaker 12 outputs an alarm sound having the adjusted sound pressure value (step S14).

  With the above procedure, the electric signal corresponding to the alarm sound output from the sound source 21 is adjusted based on the identifier 14. Then, the adjusted alarm sound is output from the speaker 12.

  Note that the above-described speaker characteristics are not limited to the sound pressure of the alarm sound output from the speaker 12, but may be the frequency band of the alarm sound output from the speaker 12, for example. In this case, the correction value described above may be a frequency correction value, and the amplification degree adjustment unit may be a frequency adjustment unit that adjusts the frequency. In this case, a filter that passes an electric signal in a predetermined frequency band or a filter that cuts an electric signal in a predetermined frequency band may be used as the frequency adjustment unit. The speaker characteristics may be both sound pressure and frequency band, or other characteristics.

  Moreover, the determination part 24 and the amplification degree adjustment part 26 may be comprised with the same apparatus by the microcomputer etc.

  As described above, the sound reproduction device 1 according to the present embodiment includes the speaker unit 10 having the speaker 12 and the identifier 14 for identifying the characteristics of the speaker 12, and the amplifier unit 20 that amplifies the sound output from the speaker 12. And. The amplifier unit 20 amplifies a signal corresponding to the sound input from the sound source 21 and outputs the amplified signal to the speaker 12, a determination unit 24 that determines the characteristics of the speaker based on the identifier 14, and the sound output from the amplifier 22. And an amplification degree adjustment unit 26 for adjusting the amplification degree. When the speaker unit 10 and the amplifier unit 20 are connected, the determination unit 24 determines the characteristics of the speaker 12 of the connected speaker unit 10 from the identifier 14 of the connected speaker unit 10. The amplification degree adjustment unit 26 adjusts the amplification degree of the sound output from the amplifier 22 in accordance with the characteristics of the speaker 12 determined by the determination unit 24.

  Thus, by providing the speaker unit 10 with the identifier 14 having speaker-specific identification information, the amplifier unit 20 determines variations in speaker characteristics such as sound pressure unique to each speaker 12, and the optimum speaker characteristics are obtained. Can be adjusted as follows. Therefore, when the speaker unit 10 and the amplifier unit 20 are connected, the alarm sound output from the speaker 12 can be accurately adjusted by determining the identifier 14 of the speaker unit 10. Therefore, a desired sound pressure characteristic can be realized no matter what speaker unit 10 and amplifier unit 20 are combined.

  In the above-described embodiment, the speaker unit 10 in the sound reproducing device 1 has the resistor 14a as the identifier 14. However, the identifier is not limited to the resistor 14a, and may be another. Below, the modifications 1-3 of this Embodiment are shown.

(Modification 1)
A first modification of the present embodiment will be described. FIG. 5 is a diagram showing a configuration of the speaker unit 30 according to this modification.

  In the embodiment described above, the speaker unit 10 in the sound reproducing device 1 has the resistor 14a as the identifier 14, but the identifier is, for example, a sound collection element that detects sound output from the speaker 12. Also good. The sound collection element is, for example, a microphone. Thereby, since the determination part 24 determines an identifier and a sound pressure level directly from the alarm sound output from the speaker 12, the amplifier 22 can adjust an alarm sound in real time.

  As shown in FIG. 5, the speaker unit 30 includes a speaker 12 and an identifier 34. The identifier 34 includes a sound collection element 34a. The sound collection element 34a is, for example, a microphone.

  The sound collection element 34 a collects the alarm sound output from the speaker 12. The alarm sound collected by the sound collection element 34 a is input to the determination unit 24 of the amplifier unit 20.

  The determination unit 24 determines the sound pressure of the collected alarm sound. For example, the determination unit 24 classifies the sound pressure of the collected alarm sound for each predetermined range. The level of the collected sound pressure is set for each predetermined level, such as level A when the sound pressure level is low, level B when the sound pressure level is medium, and level C when the sound pressure level is high. judge.

  The amplification degree adjustment unit 26 adjusts the amplification degree of the amplifier 22 based on the determination result of the identifier 34 determined by the determination unit 24 as in the above-described embodiment. Subsequently, the amplifier 22 outputs the adjusted electrical signal to the speaker 12. Thereby, the speaker 12 outputs an alarm sound having the adjusted sound pressure value.

  With the above procedure, the electric signal corresponding to the alarm sound output from the sound source 21 is adjusted based on the identifier 34. Then, the adjusted alarm sound is output from the speaker 12.

  The sound collection element 34a is not limited to a microphone, and may be a speaker. This is because the speaker not only emits sound by changing electrical signals into mechanical vibrations, but can also collect sound by changing mechanical vibrations into electrical signals.

(Modification 2)
Next, Modification 2 will be described. FIG. 6 is a diagram showing the configuration of the speaker unit 40 according to this modification.

  The identifier in the speaker unit may be, for example, a vibration detection element that detects vibration of the speaker 12. A piezoelectric element may be used as the vibration detection element. Thereby, the determination unit 24 directly determines the identifier and the sound pressure level by detecting the vibration of the speaker 12 corresponding to the alarm sound, so that the amplifier 22 can adjust the alarm sound in real time. Further, by using the piezoelectric element, mechanical vibration called vibration of the speaker 12 can be efficiently converted into an electric signal, and adjustment can be easily performed.

  A magnetostrictive element may be used as an alternative to the piezoelectric element.

  As shown in FIG. 6, the speaker unit 40 includes a speaker 12 and an identifier 44. The identifier 44 includes a piezoelectric element 44a that is a vibration detection element.

  The piezoelectric element 44 a is fixed to the speaker 12, and expands and contracts in response to vibration of the speaker 12 when an alarm sound is output from the speaker 12. The piezoelectric element 44a is provided with a terminal for outputting a voltage. An electrical signal is output from the piezoelectric element 44a via this terminal. That is, the piezoelectric element 44 a converts mechanical vibration called expansion / contraction into an electrical signal corresponding to the magnitude of the vibration amplitude of the speaker 12 and outputs the electrical signal to the determination unit 24.

  The determination unit 24 determines the sound pressure of the alarm sound output from the piezoelectric element 44a. For example, the determination unit 24 divides the vibration amplitude of the speaker 12 that is converted from mechanical vibration into an electrical signal and output to the determination unit 24 for each predetermined range. The magnitude of the vibration amplitude of the speaker 12 is level A when the vibration amplitude of the speaker 12 is small, level B when the vibration amplitude of the speaker 12 is medium, and level C when the vibration amplitude of the speaker 12 is large. Are determined for each predetermined level.

  The amplification degree adjustment unit 26 adjusts the amplification degree of the amplifier 22 based on the determination result of the identifier 44 determined by the determination unit 24 as in the above-described embodiment. Subsequently, the amplifier 22 outputs the adjusted electrical signal to the speaker 12. Thereby, the speaker 12 outputs an alarm sound having the adjusted sound pressure value.

  With the above procedure, the electric signal corresponding to the alarm sound output from the sound source 21 is adjusted based on the identifier 44. Then, the adjusted alarm sound is output from the speaker 12.

  Note that the vibration detection element constituting the identifier 44 may not be the piezoelectric element 44a, and may be a light detection element that detects vibration by light, for example, as shown in Modification 3 below. Hereinafter, Modification 3 will be described.

(Modification 3)
Next, Modification 3 will be described. FIG. 7 is a diagram showing the configuration of the speaker unit 50 according to this modification.

  The identifier in the speaker unit may be a vibration detection element that detects vibration of the speaker 12. Specifically, the vibration detection element may be configured by a light detection element 54b. Thereby, since the determination part 24 determines an identifier and a level directly from the vibration of the speaker 12 corresponding to the alarm sound, the amplifier 22 can adjust the alarm sound in real time. Moreover, since the vibration of the speaker 12 is detected in a non-contact manner using light, it is possible to perform an accurate adjustment.

  As shown in FIG. 7, the speaker unit 50 includes a speaker 12 and an identifier 54. The identifier 54 includes a light output element 54 a and a light detection element 54 b that detects light output from the light output element 54 a and reflected by the speaker 12. As the light output element 54a, for example, a laser element that outputs laser light may be used. As the light detection element 54b, a light receiving element such as a light sensor or a solid-state imaging element may be used. The identifier 54 only needs to include at least the light detection element 54 b, and the light output element 54 a may be externally attached to the identifier 54.

  The light output element 54 a emits light toward the speaker 12. The light emitted from the light output element 54a is reflected by the speaker 12 and detected by the light detection element 54b. The light detection element 54 b detects reflected light corresponding to the vibration of the speaker 12 or the vibration of the diaphragm of the speaker 12 when an alarm sound is output from the speaker 12. The light detection element 54b detects an optical signal corresponding to the reflected light, converts it into an electrical signal, and outputs it to the determination unit 24.

  The determination unit 24 determines the sound pressure of the alarm sound output from the light detection element 54b. For example, the determination unit 24 divides the vibration amplitude of the speaker 12 that is converted from an optical signal into an electrical signal and output to the determination unit 24 for each predetermined range. The magnitude of the vibration amplitude of the speaker 12 is level A when the vibration amplitude of the speaker 12 is small, level B when the vibration amplitude of the speaker 12 is medium, and level C when the vibration amplitude of the speaker 12 is large. Are determined for each predetermined level.

  The amplification degree adjustment unit 26 adjusts the amplification degree of the amplifier 22 based on the determination result of the identifier 44 determined by the determination unit 24 as in the above-described embodiment. Subsequently, the amplifier 22 outputs the adjusted electrical signal to the speaker 12. Thereby, the speaker 12 outputs an alarm sound having the adjusted sound pressure value.

  With the above procedure, the electrical signal corresponding to the alarm sound output from the sound source 21 is adjusted based on the identifier 54. Then, the adjusted alarm sound is output from the speaker 12.

  In the above description, the identifier on the speaker unit side is connected to the amplifier unit 20 to receive a signal necessary for the identification as information. However, the reception of such information is other than direct connection. In addition, it may be configured to be indirectly connected by wireless communication. In this case, the power required for wireless communication can be determined by transmitting information by wireless communication only for the first connection using a part of the direct current component of the output from the amplifier 22 for identification.

  Although the sound reproducing device according to the embodiment and the modification of the present invention has been described above, the present invention is not limited to the embodiment and the modification.

  At least a part of the processing unit included in the sound reproduction device according to the above-described embodiment may be realized as an LSI that is an integrated circuit. These may be individually made into one chip, or may be made into one chip so as to include a part or all of them.

  Further, the circuit integration is not limited to LSI (Large Scale Integration), and may be realized by a dedicated circuit or a general-purpose processor. An FPGA (Field Programmable Gate Array) that can be programmed after manufacturing the LSI or a reconfigurable processor that can reconfigure the connection and setting of circuit cells inside the LSI may be used.

  That is, in the above-described embodiments and modifications, each component may be configured by dedicated hardware or may be realized by executing a software program suitable for each component. Each component may be realized by a program execution unit such as a CPU (Central Processing Unit) or a processor reading and executing a software program recorded on a recording medium such as a hard disk or a semiconductor memory.

  Moreover, all the numbers used in the above are examples for specifically explaining the present invention, and the present invention is not limited to the illustrated numbers.

  In addition, division of functional blocks in the block diagram is an example, and a plurality of functional blocks can be realized as one functional block, a single functional block can be divided into a plurality of functions, or some functions can be transferred to other functional blocks. May be. In addition, functions of a plurality of functional blocks having similar functions may be processed in parallel or time-division by a single hardware or software.

  The order in which the plurality of steps shown in the above-described flowchart and the like are executed is for illustrating the present invention specifically, and may be in an order other than the above. Also, some of the above steps may be executed simultaneously (in parallel) with other steps.

  As mentioned above, although the sound reproduction apparatus concerning one or several aspects was demonstrated based on embodiment, this invention is not limited to this embodiment. Unless it deviates from the gist of the present invention, various modifications conceived by those skilled in the art have been made in this embodiment, and forms constructed by combining components in different embodiments are also within the scope of one or more aspects. May be included.

  The present invention can be applied to a sound reproducing device mounted on a low noise vehicle such as an electric vehicle and a hybrid vehicle.

DESCRIPTION OF SYMBOLS 1 Sound reproduction apparatus 10, 30, 40, 50 Speaker unit 12 Speaker 14, 34, 44, 54 Identifier 20 Amplifier part 21 Sound source 22 Amplifier 24 Judgment part 26 Amplification degree adjustment part 34a Sound collection element 44a Piezoelectric element (vibration detection element)
54a Light output element 54b Light detection element (vibration detection element)

Claims (6)

A speaker unit having a speaker and an identifier for identifying characteristics of the speaker;
An amplifier for amplifying a signal corresponding to the sound to be output from the speaker;
The amplifier section is
An amplifier that amplifies the signal input from a sound source and outputs the amplified signal to the speaker;
A determination unit for determining the characteristic of the speaker by the identifier;
An amplification degree adjustment unit for adjusting the amplification degree of the signal output from the amplifier;
When the speaker unit and the amplifier unit are connected,
The determination unit determines the characteristic of the speaker of the connected speaker unit from the identifier of the connected speaker unit,
The amplification adjustment unit adjusts the amplification of the signal output from the amplifier in accordance with the characteristic of the speaker determined by the determination unit. The sound reproducing device according to claim 1, wherein the identifier is a resistor having a resistance value corresponding to the characteristic of the speaker. The sound reproduction device according to claim 1, wherein the identifier is a sound collection element that detects sound output from the speaker. The sound reproduction device according to claim 1, wherein the identifier is a vibration detection element that detects vibration of the speaker. The sound reproduction device according to claim 4, wherein the vibration detection element is configured by a piezoelectric element. The sound reproduction device according to claim 4, wherein the vibration detection element is configured by a light detection element.

Images